We're not, basically because none (?) of our resources are Persian Gulf-style money printers. Like, we have oil, but it needs a whole lot of work to get from tar sand to gas tank. Down there it gets close to just sticking a straw in the ground.
The end result is that we're still one of the richest countries per capita, we just spend a lot of man hours on farming. mining and drilling, instead of on manufacturing like they do in Germany or Japan.